Quasi-One-Dimensional Transition-Metal Chalcogenide Semiconductor (Nb 4 Se 15 I 2 )I 2
Quasi-One-Dimensional Transition-Metal Chalcogenide Semiconductor (Nb 4 Se 15 I 2 )I 2
复制标题
准一维过渡金属硫族化物半导体 (Nb 4 Se 15 I 2 )I 2
DOI：
10.1021/acs.inorgchem.2c03796
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发表时间：
2023
影响因子：
4.6
通讯作者：
de Juan, Fernando
中科院分区：
文献类型：
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作者：
Qu, Kejian;Riedel, Zachary W.;Sánchez-Ramírez, Irián;Bettler, Simon;Oh, Junseok;Waite, Emily N.;Woods, Toby J.;Mason, Nadya;Abbamonte, Peter;de Juan, Fernando
新的低维过渡金属硫族化合物的发现为这些材料的繁荣家族做出了贡献。本研究采用化学气相输运法制备了准一维（1D）材料（Nb4Se15I2）I2的针状单晶，并用单晶x射线衍射（XRD）对其结构进行了解析。该结构具有沿[101]方向的1D (Nb4Se15I2)n链，每个分子式单元有两个i离子直接与Nb5+键合。另外两个i -离子松散地配位并插在链之间。单个链是手性的，沿轴方向相反堆叠，形成空间群pp21 /c。通过粉末XRD对相纯度和晶体结构进行了验证。密度泛函理论计算表明（Nb4Se15I2） i2是一种直接带隙约为0.6 eV的半导体。块状晶体和微图案化器件的电阻率测量表明，（Nb4Se15I2） i2的活化能约为0.1 eV，冷却后未见异常或转变。低温XRD表明（Nb4Se15I2） i2在室温至8.2 K时不发生结构相变，而相关化合物（NbSe4）nI （n= 2、3或3.33）均表现出电荷密度波。该化合物是各向异性过渡金属硫属化合物中表征良好、价精确的一种。
The discovery of new low-dimensional transition-metal chalcogenides is contributing to the already prosperous family of these materials. In this study, needle-shaped single crystals of a quasi-one-dimensional (1D) material, (Nb4Se15I2)I2, were grown by chemical vapor transport, and the structure was solved by single-crystal X-ray diffraction (XRD). The structure has 1D (Nb4Se15I2)nchains along the [101] direction, with two I–ions per formula unit directly bonded to Nb5+. The other two I–ions are loosely coordinated and intercalated between the chains. Individual chains are chiral and stack along thebaxis in opposing directions, giving space groupP21/c. The phase purity and crystal structure were verified by powder XRD. Density functional theory calculations show (Nb4Se15I2)I2to be a semiconductor with a direct band gap of around 0.6 eV. Resistivity measurements of bulk crystals and micropatterned devices demonstrate that (Nb4Se15I2)I2has an activation energy of around 0.1 eV, and no anomaly or transition was seen upon cooling. Low-temperature XRD shows that (Nb4Se15I2)I2does not undergo a structural phase transformation from room temperature to 8.2 K, unlike related compounds (NbSe4)nI (n= 2, 3, or 3.33), which all exhibit charge-density waves. This compound represents a well-characterized and valence-precise member of a diverse family of anisotropic transition-metal chalcogenides.